The station currently consists of a single swapping bay, along with a second bay that's presumably for deliveries.

The Tesla Model S was designed from the start to enable swapping, which has the added benefit of making battery installation easier on the assembly line in Tesla's factory in Fremont, California.

But it's not clear how much consumer demand exists for battery swapping.

Tesla's Supercharger DC quick-charging is free to all Model S owners whose cars have the capability, which takes 20 to 30 minutes to recharge the car's battery to 80 percent of capacity.

To swap for a fully-charged pack, however, Tesla owners will have to pay a fee — not yet specified, but thought be $50 to $60 — to reduce their "recharge" time to a few minutes.

The only other major implementation of battery swapping was built by now-bankrupt Israeli electric-car service Better Place. Those stations are now all defunct.

The test site isn't expected to offer the same, fully automated 90-second swapping shown off by Musk in June 2013. Instead, it will likely involve a combination of automated and manual steps by on-site staff.

Much speculation has centered around the reasons Tesla pledged to offer pack swapping.

Many of the suggestions note that Tesla receives a higher number of credits for sales of its zero-emission vehicles from the California Air Resources Board (CARB) if the vehicle can "refuel" at the same rate as a gasoline vehicle for roughly similar range.

Sometime soon, one or more Tesla owners will be able to get that experience first-hand — after making their appointment beforehand.